The present invention concerns a system for the impregnable locking of the fastening of display boxes commonly known as "blisters"; they consist firstly of box with two articulated halves destined to receive the product to be sold, and secondly of fastening parts, respectively interdependent of the halves, that are to be held one against the other by a fastening system, supposedly impregnable.
To avoid shoplifting, these blisters are of large sizes, therefore cannot be hidden, and only the personnel at the store's cash register have a device that allows it to open the fastening system and to give the product to the buyer.
However, the risks of theft remain high, since the blisters themselves, or their fastening system, can still be broken open, their impregnability being illusory.
The invention brings a satisfactory solution to this problem, due to a novel conception of these fastening parts and their immobilization system.